Plasma enhanced substrate processing is commonly used, for example, in the manufacture of semiconductor devices and integrated circuits. Such processing generally includes introducing a process gas into a process chamber having a substrate, such as a semiconductor wafer, disposed therein and applying sufficient energy to the process gas to form a plasma over the substrate. The plasma contains dissociated and ionized components as well as neutral components that operate to assist the process being performed on the substrate (such as deposition, etching, and the like). Although the constituents of the plasma are beneficial for assisting or carrying out the process on the substrate, unconstrained plasma components may impinge on the substrate and/or chamber components causing damage. In addition, plasma non-uniformities may lead to non-uniform processing of substrates.
To control the plasma, conventional process chambers may include a magnetic field forming device configured to produce a magnetic field within the process chamber to constrain plasma components. However, the magnetic field produced by such conventional configurations typically comprise non-parallel and non-planar magnetic field lines, resulting in non-uniform plasma confinement, and therefore, non-uniform processing of the substrate.
Therefore, the inventors have provided an improved apparatus for controlling a plasma and methods of use thereof.